1. Field of the Invention
This invention relates to a device to limit the dynamic pressure in an engine exhaust brake wherein a butterfly valve is movably supported in an exhaust pipe to be deflected from an open position into a closed position.
2. Description of the Prior Art
In a prior-art device of this type German Utility Pat. No. 84 24 212, which corresponds to co-pending U.S. patent application Ser. No. 763,216, filed Aug. 7, 1985, now U.S. Pat. No. 4,682,674, the butterfly valve in its closed position also contacts the end face of the poppet valve head and the spring has a characteristic about whose rate of rise nothing is stated. During tests using this device, the safety valve failed to respond either when the upper dynamic pressure limit was exceeded by a small amount or when the upper dynamic pressure limit was considerably exceeded.